fairness-lab

# Fairness Lab

Fairness Lab computes observability metrics for sequencing outcomes.

## Required ingest
To compute real ordering distance (Dτ), Mallet needs a "first-seen" timestamp for signatures.

Mallet provides:
- `POST /api/ingest/seen` with `{ signature, seenAtMs?, source }`

Once first-seen data exists, Mallet computes:
- Dτ (Kendall tau distance): arrival order vs execution order
- C(W): lock contention index
- Starvation: tail inclusion latency by signer/program
- χ²: error distribution shifts (clustering)
- Gini: inequality of inclusion latency

## Why this matters
This produces governance-ready reports without requiring access to private BAM internals.